# Four-layer nanocomposite structure as an effective optical waveguide switcher for near-IR regime

## TL;DR

This paper theoretically analyzes a four-layer nanocomposite optical waveguide structure that enables polarization switching and power control in the near-infrared regime, with potential applications in integrated photonics.

## Contribution

It introduces a novel four-layer nanocomposite waveguide design with an original algorithm for guided mode identification and demonstrates polarization switching capabilities.

## Key findings

- Achieved a power switching ratio of about 6 dB within 100 nm wavelength range.
- Demonstrated polarization switching of TE and TM modes based on layer geometries.
- Provided dispersion diagrams and field profiles illustrating propagation changes.

## Abstract

We present a theoretical study of the dispersion and energy properties of the eigenwaves (TE- and TM- modes) in a four-layer structure composed of a magneto-optical yttrium iron garnet guiding layer on a dielectric substrate covered by a planar nanocomposite guiding multilayer. The bigyrotropic properties of yttrium-iron garnet are taken into account for obtaining the dispersion equation and an original algorithm for the guided modes identification is proposed. We demonstrated the polarization switching of TE- and TM-modes dependent on the geometrical parameters of the guiding layers. The dispersion diagrams and field profiles are used to illustrate the change of propagation properties with variation of the multilayer thickness ratio of the nanocomposite layers. The energy flux distributions across the structure are calculated and the conditions of the optimal guiding regime are obtained. The power switching ratio in the waveguide layers of about 6 dB for the wavelength range of 100 nm is shown to be achieved.

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Source: https://tomesphere.com/paper/1903.00854